Keybase client
Keybase Go library, client, service, OS X, iOS, Android, Electron
...We use public key cryptography to ensure your messages stay private. Even we can’t read your chats. Keybase works for families, roommates, clubs, and groups of friends, too. Keybase connects to public identities, too. You can connect with communities from Twitter, Reddit, and elsewhere. Don’t live dangerously when it comes to documents. Keybase can store your group’s photos, videos, and documents with end-to-end encryption. You can set a timer on your most sensitive messages. This distribution includes cryptographic software. The country in which you currently reside may have restrictions on the import, possession, use, and/or re-export to another country, of encryption software. ...